The utility model discloses an Ethernet-based current differential protective device comprising a clock module, a collecting module, an Ethernet communication interface module, a data receiving module, a data sending module, a synchronous module and a differential calculating module, wherein the clock module is connected with the collecting module through a circuit; the collecting module is respectively connected with the synchronous module and the data sending module through circuits; the data sending module is connected with the Ethernet communication interface module through a circuit; the Ethernet communication interface module is connected with the data receiving module through a circuit; the data receiving module is connected with the synchronous module through a circuit; the synchronous module is connected with the differential calculating module through a circuit; and the Ethernet communication interface module is in bidirectional connection with the Ethernet through a circuit. According to the utility model, the differential protective device is connected with the Ethernet, differential protection sampling data are received and sent according to the IEC61850-9-2 standard, and the Ethernet-based current differential protective device has the characteristics that the differential protective application range is expanded and the communication service investment cost is reduced.